The present invention relates generally to window structures for buildings, vehicles or other applications, and more particularly to a blast resistant window capable of withstanding blast pressures from accidental explosions, or bomb blasts from a car bomb or terrorist attack.
A terrorist attack with explosives, chemical, and/or biological weapons is a potential threat to both the civilian population and military forces. One of the weakest points on a structure is the window and transparent glass area. Many casualties may result from shattered and flying glass. Additional casualties may result from subsequent chemical and or biological weapon exposure caused by the air leaks created by the broken window. The present invention provides a novel blast resistant window structure that resists the blast pressures generated by an explosive device and prevents glass and chem-bio injuries.
The combined threat of blast with chemical or biological weapons imposes major engineering demands on a window structure to resist extremely high blast pressures, and to maintain a seal to prevent entry of chemical or biological contaminants. Previous solutions to the threat of a blast combined with either a chemical or biological weapon (combined threat) have treated the two parts of the combined threat as two separate, isolated problems. Generally, in the past, a higher priority has been given to the blast resistance portion of the combined threat. However, presently, separate solutions are insufficient to combat the combined threat.
Prior art structures for blast resistant windows field have included the application of a safety film to the interior side of the glass, using laminated glass, using double pane glass and/or using a thicker glass pane. None of these structures have demonstrated a capability for resisting blast loads on the order of 100 psi reflected pressure. Currently available, commercial off-the-shelf, blast-resistant windows typically fail at blast pressures well below 10 psi, and usually can withstand blast pressures of only about 4 psi. The ability to withstand extremely high blast pressures, yet remain leak-proof, is a unique attribute of the invention described herein.
Information related to the principles underlying the invention may be found in Dover et al, “Sealed Window Glazing System for Chemical Biological Protected Space Applications,” Proceedings, NBC Defense Collective Protection Conference (COLPRO 02), Orlando Fla. (2002), contained in the cross-referenced related application, and in “Sealed, Blast-Resistant Windows for Retrofit Protection Against the Terrorist Threat,” Proceedings, 2nd International Conference on Innovation in Architecture, Engineering and Construction (AEC), Loughborough University UK (2003), the entire teachings of which are incorporated herein by reference.
It is a principal object of the invention to provide a blast resistant window structure.
It is another object of the invention to provide a window structure resistant to blast pressures up to about 100 psi.
It is another object of the invention to provide a blast resistant window having a protection against leaking of biological or chemical substances through the window structure.
It is another object of the invention to provide a window structure resistant to glass shard impact.
It is yet another object of the invention to provide a blast resistant window structure resistant to Catastrophic failure that would result in glass shard injuries.